Counterbalancing device



E. G. ANDERSON COUNTERBALANCING DEV-ICE Filed Dec. 24, 1929 Aug, 3%,132.

Ti -l.

ATTORNEYS.

Patented Aug. 30, 1932 UNITED STATES,

ELLIs G. ANDERSON, OF OKLAHOMA CITY, OKLAHOMA cOUfirEnBALANcmG DEVICEApplication filed December 24, 1929.

This invention relates to a counterbalancing device which is designedand adapted to operate in conjunction with curtains or doors which arewound on and unwound from an Ll! overhead winding core, roller orbarrel,and

also to operate in conjunction with any appurtenances whose weightvaries in operation under the influence of a directgravity ull. P Theprincipal object of the invention is the provision of a device of theindicated character having means for making the desired adjustments, tocompensate for any variations in the widths of curtains, doors and thelike, and corresponding variations in weights of curtains, doors and thelike of the same size, but made of materials of various weights.

With the foregoing, other objects of the invention will appear from theembodiment of the invention which by way of example is described in thefollowing specification and illustrated in the accompanying drawing, inwhich I Figure 1 shows the device of the present invention applied byway of example to a roller door, the same being rolled up, and a portionthereof being broken away;

Figure 2 is a section on the line 22 of Figure 1 looking in thedirection indicated by the arrow;

Figure 3 is an end view of the pulley;

Figure 4 is a fragmentary face view of the grooved part of the pulley.

As stated, the device of the present invention is one which may beemployed in conjunction with a curtain or door which is wound on andunwound from a suitable winding core, roller or barrel. In Figure 1 ofthe drawing there is shown an axle or shaft mounted for rotation insuitable bear-.

Serial No. 416,283.

tion of gravity. It will be understood that the weight imposed on theaxle 10 as the door is wound and unwound will vary.

. In other words, the weight or force imposed on the axle 10 increasesas the door is u unwound, and decreases as the door is wound on thebarrel 12.

The device of the present invention includes a pulley 14 consisting of apart 15 and a part 16. The part 15 is of conical form, and has a helicalgroove 17, the convolutions of which increase progressively from thesmall end to the large end of the part 15. The part 15 is looselymounted on one end of the axle 10. I

The part 16 of the pulley is in the form of a disk having a hub 18 whichcarries a set screw 19. The part 16 is adapted to be mounted on the axleend adjacent the part 15 and is securely held in place thereon by I0 theset screw 19. Use is made of a weight 20 of suitable size and a flexibleelement 21 such as a cord which has one end thereof connected with theweight 20 and the opposite end thereof is detachably connected by 76 aheaded element 22 with the part 15 of the pulley. The part 15 has aplurality of holes 28 any one of which is adapted to'accommodate theelement 22 to change the connection of the flexible element 21 with thepart 15, for the purpose of making the desired adjustment to compensatefor variations in the weight of the door, to a limited extent.

In order to further adjust the parts of the pulley to compensate forvariations in the weight so that the proper counterbalancing efl'ect maybe obtained, the part 16 is provided with a series of holes 24 arrangedconcentrically with respect to the axis of the part 16, and the part 15of the pulley has a plurality of threaded holes 25. Use is made of setscrews 26 equal in number to the number of'holes 25. The set screws 26are receivable respectively in certain of the holes 95 24 of the part 16andare threaded in holes 25 of the part 15 to securely hold the parts 15and 16 of the pulley in the desired adjusted relationship. In thismanner the necessary and desired adjustment of the pulley 14 may be madeto com ensate for variations for the reasons state herein above.

From the foregom 1t W111 be apparent that when the door 13 1s wound uponthe bar.-

rel 12, the flexible element 21 will be unwound from the part 15 of thepulley with the counterbalancin g weight 20 in the down posltion. Whenthe door 13 is unwound from the barrel 12, the flexible element 21 willwind .on the part 15 of the pulley, thereby raismg the counterbalancingweight 20, which serves to counterbalance the increasing weight of thedoor as it is being unwound from the barrel 12. 1

I claim:

1. A counterbalancing device of the class described including arotatable axle, a pulley adapted for winding thereon and unwinding 1therefrom a counter-weight flexible sustaining element, said pulleycomprising a part for said element loosely. mounted on said axle, a partfixed on said axle, and means adapted to secure said parts together inany;

desired adjusted relation with respect to cite other.

2. A counterbalancijng device of the class 7 described including arotatable axle, a pulley adapted for winding thereon andunwindingtherefrom a counter-weight flexible sustaining element, saidpulley comprising a part'for said element loosely mounted on said axle,a part fixed on -said axle, and

securing means on said parts to connectsaid w parts togetherin anydesired adjusted relation with respect to each other.

3. A counterbalancing device of the class described including arotatable axle, a pulley adapted for winding thereon and unwindingtherefrom a counter-weight flexi ble sustaining element, said pulleycomprising a part for said element loosely mounted on said axle, a partfixed on said axle, each of said parts having apertures therein, theapertures in one'part being arranged to be brought into registry withthe apertures in the other part, and the sides of theapertures;

in the latter part each being threaded, and

fastening elements receivable respectively in the apertures in one partand capableof be ing threaded in the registeringapertures' in the otherpart for the purpose specified.

ELLI G. ANDERSON,

